The present invention relates to a socket of integrated circuits, and particularly to a socket of integrated circuits which is modularized and replaceable.
With the rapid development of semiconductor industry these years, when the density of integrated circuits (ICs) becoming bigger and bigger, the line width decreased to sub-micron range, even deep sub-micron. Nevertheless, the lifetime of the integrated products becoming shorter. Since the variable requirement with ICs also increased, there are products with different functions, sizes, and pin assignment.
In the processing steps of semiconductor devices, there are many testing steps after IC devices completed to ensure the functionality and quality of the IC devices. For example, the testing steps of an IC chip may include the testing of lead frame, the power consumption, the basic logic and output voltage level in a xe2x80x9cburn inxe2x80x9d test. The basic hardware structure of these testing is to use a socket or a connector to locate the IC chip.
Conventional connectors of IC chips such as logic circuits for central processing unit (CPU) or memory circuits are all with specific usage and pin assignment, therefore the sockets they use are always welding on the printing circuit board (PCB) and are not replaceable. Furthermore, the conventional sockets for locating the IC chip are soldered on the PCB and are designed for specific kind of IC chip. The clamping structure of the socket is used to fix the IC device and conduct it for testing. That is, the testing IC socket of this kind is not replaceable.
However, since the life cycle of the IC devices are very short, it is possible that the IC sockets and the connected PCB are useless after the IC products are not produced any more. Moreover, a new socket is redesigned for another IC device. Further, since the conventional testing IC sockets are welding on the PCB, it is not easy to repair the sockets in case one of the sockets is damaged. One way to repair the damaging socket is to release the welding parts of the socket and pull out of the PCB, then re-soldering another socket on the board for the subsequent testing. Nevertheless, the repair work of this kind is not economical and wasting manpower.
Briefly, the conventional IC socket is fastened on the testing printed circuit board and is not easy to replace when the socket is damaged. Besides, a conventional socket can only fit a specific pitch number of IC device. Therefore, there is a need of a new IC socket in the testing field of the IC device.
The main object of the present invention is a modularized IC socket used for testing, part of the modules can be replaced to suit for different types of IC devices.
Another object of the present invention is to use a modularized IC socket to save the manpower and the cost.
A further object of the present invention is to use a modularized IC socket to fit the future need of fine pitch IC device.
In the first preferred embodiment of the present invention, the modularized IC socket comprised:
(1) A base unit: It further includes a base, contact pins, and an elastomer. There are recessed portions in the base to locate the elastomer and contact pins. One end of the contact pin is a straight end to stretch out of the lower portion of the base and solder on the printed circuit board, another end of the contact pin is a portion with a U shape cantilever to stretch out of the upper portion of the base and contact with other element. The elastomer has elasticity and compressibility to provide a good electrical contact.
(2) An interposer: The interposer is the interface of the IC chip and the base unit. It further includes contact pads, accepters and conducting wires on the conducting surface. The accepter is connected to the solder balls of IC chip, through the joined conducting wires with the contact pad and the connected contact pin to achieve the function of electrical connection. There are positioning holes in the interposer to align with the underneath base unit.
(3) An adapter unit: The adapter unit is placed on the base unit and the interposer. It further includes an adapter base, a depressor, and a shaft. The adapter unit provides the positioning function of the IC chip, and the depressor is rotated about the shaft to suppress or release the IC chip.
(4) A cover unit: The unit is located over the base unit, the interposer, and the adapter unit. It further includes a cover and springs. The cover unit will move up and down vertically, wherein when the cover unit press downward, the coupling depressor of the adapter unit will rotate to free the IC chip, though when the cover unit pull upward, the depressor is suppressed on the IC chip to keep a good electrical contact.
The modularized IC socket of the first preferred embodiment of the present invention is suitable for an array type IC chip package. When the pin assignment of the IC chip are changed, the interposer can be redesigned to fit the different IC chip, or change the adapter unit and the cover unit at most. Nevertheless, the bottom base unit will keep on the PCB.
The second preferred embodiment of the present invention is summaries as follows:
(1) The base unit: The base unit includes a base and contact pins as the first embodiment. One end of the contact pin is welding on the PCB and another end of the contact pin is electrically connected with the upper device.
(2) The interposer: The interposer is an interface of the lower base unit and the upper adapter unit; there are contact pads and conducting wires thereon to provide the electrical connection.
(3) The adapter unit: The unit is located over the base unit and the interposer and it further includes an adapter and contact pins. Contact pins is recessed in the adapter with one end electrically connect to the underneath contact pads of the interposer, and another end with an elastic U shape cantilever and a protrusion to electrically connect to the IC device.
(4) The cover unit: The unit is placed on the base unit, the interposer, and the adapter unit and it further includes a cover and springs. The cover unit can move up and down vertically to suppress or release the IC chip. There is a inclined plane in the cover unit to couple with one end of the contact pin in the adapter unit, the movement of the cover unit will cause the contact pin become a stretched position or recover to a normal position.
The modularized IC socket of the second embodiment of the present invention is suitable to a lead frame type IC chip package. Furthermore, the replaceable parts of the socket fit the requirement of different sizes or pin assignment of the IC chip.